Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.  The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.  Thus it is the challenge of competition among males of the species that facilitates aggression and violence.  Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.  The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males. 
Before the Evolution of Combat, when fighting in the aggressive stance , $ $ Strength experience was awarded per hit, where $ x $ is the amount of damage dealt. Fighting using the controlled stance , however, awards $ $ Strength experience per hit, where $ x $ is the amount of damage dealt. For example, a player who hits a 10 would receive 4 Strength experience when fighting in the aggressive stance and Strength experience when fighting in the controlled stance. The amount of experience received when fighting in the controlled stance may be calculated in the same way that experience awarded to the Constitution skill is calculated.